Light from Sand (podcast 2:00) - LEDs or light emitting diodes are everywhere from traffic lights to Christmas ornaments to remote controls. Inside these tiny bulbs is a small grey block which is made of silicon. And, silicon has the unusual origin of coming from sand.
A light-emitting diode (LED) is a two-lead semiconductor light source. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared light. The first visible-light LEDs were also of low intensity, and limited to red. Modern LEDs are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.
Infrared LEDs are still frequently used as transmitting elements in remote-control circuits, such as those in remote controls for a wide variety of consumer electronics.
LEDs have many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching.
Light-emitting diodes are now used in applications as diverse as aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, camera flashes and lighted wallpaper.
Light from Sand (podcast 2:00) - LEDs or light emitting diodes are everywhere from traffic lights to Christmas ornaments to remote controls. Inside these tiny bulbs is a small grey block which is made of silicon. And, silicon has the unusual origin of coming from sand.
A light-emitting diode (LED) is a two-lead semiconductor light source. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared light. The first visible-light LEDs were also of low intensity, and limited to red. Modern LEDs are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.
What's the problem?
That's engineering
Engineering ideas
Do It
Challenges for you to work on...
News, updates
Learn more...
..r0 0e 0a